Clearly there should be an entire big bang revolving around the Winchester's experimental drug use.

Sam writes in the journal: Today, I dropped acid. I'm not sure why they call it dropping it, because I was very meticulous and didn't spill any. It was an interesting experience. I had a very pressing urge to stick my nether bits up Dean's nose. He dissuaded me with a punch to the head.

My head still hurts. In summation: acid, not very fun.